基于GPRSIM的水下砂层探地雷达正演  

Forward simulation of the underwater sand based on GPRSIM software

作　　者：谢磊磊[1] 蒋甫玉[1] 常文凯[1] 

机构地区：[1]河海大学地球科学与工程学院,江苏南京210098

出　　处：《物探与化探》2015年第6期1257-1260,1266,共5页Geophysical and Geochemical Exploration

基　　金：江苏省自然科学基金项目(BK20140844);江苏省地质矿产勘查局科研技改项目(2014-KY-15)

摘　　要：基于水和岩土介质的介电常数差异,应用GPRSIM软件研究在不同水深条件下二层介质的雷达响应特征。一般情况下,雷达天线频率为50 MHz时,勘探深度可达到10 m左右。根据南京长江二桥桥址区的地质资料,建立含有水、淤泥质粉质黏土、粉细砂、砂砾卵石以及砾岩的水下砂体模型,并应用GPRSIM软件对该模型进行正演研究。研究结果表明,天线频率为50 MHz、水深不超过4 m时,雷达影像能够较好地反映出水下各岩层的赋存状态,特别是能够圈定出水下砂层的厚度和分布范围,这为实际水下砂体的勘探提供了重要的理论依据。Based on the difference of permittivity between water and rock media,the authors conducted forward simulation of two-floor geology at different depths of water by GPRSIM software. Under normal circumstances,when the radar antenna frequency is 50 MHz,the exploration depth is about 10 m. In combination with the geological data of the bridge site area of the Nanjing Yangtze River Bridge,the authors established the underwater sand model which contains water,silty clay,silty sand,gravel pebble and conglomerate,and made forward simulation of the model based on GPRSIM software. The result shows that,when the antenna frequency is 50 MHz,the maximum depth of water is less than 4m,and each rock formation under the water has a good reflection. In particular,the geological radar can better reflect the thickness and distribution range of the underwater sand. The results achieved by the authors provide important theoretical basis for the actual exploration of the underwater sand.

关 键 词：探地雷达 FDTD 正演 GPRSIM软件 水下砂层 工程勘察 

分 类 号：P631[天文地球—地质矿产勘探]